An automatic steering system may be used for guiding a self-propelled harvesting machine with a desired alignment to a crop, among other possible applications. Steering systems for harvesting crop in rows usually utilize mechanical sensing devices interacting with the crop. Such sensing devices are mounted to the crop dividers of the header and comprise movable arms abutting the plants, stems or stalks and sensors for detecting the position or displacement of the arms.
In one illustrative prior art configuration for mounting the sensing device, arms extend through assigned openings in a modified crop divider. However, the openings tend to structurally weaken the crop divider. Further, in weedy or dense crop conditions, debris and crop residues tend to collect at the openings, reducing the performance of the crop divider and the sensing device.
There are several common problems associated with sensing devices for detecting the relative locations of one or more plants (e.g., stalks within rows) with respect to the harvesting machine with a header or similar implement configuration. First, if the sensing devices are mounted at the underside of the crop divider of the header, they are exposed to debris and objects on the ground and can be damaged. Further, for such sensing devices, the mobility of the arms becomes restricted due to the collected debris. Second, if the header is operated too close to the ground, the arms encounter the ground instead of the plants and provide incorrect signals to the steering system. Third, the plants are growing on ridges or mounds, the arms will encounter the ridge instead of the crop. Thus, there is a need for an improved sensing assembly.